Minor tears found in Brown's retina

Downing Street took the unusual step of revealing the results of medical check-ups amid intense speculation over the Prime Minister's health.

But a spokesman insisted that his vision was not getting worse, and he would not need further surgery.

"This summer Mr Brown had his annual eye check-up which was fine. Later he had his retina checked," the spokesman said. "After examinations surgeons found that the retina had two minor tears. However, as there has been no further deterioration, and no change in his eyesight, they decided against further operations.

"Yesterday Mr Brown visited Moorfields Hospital as part of regular checks on his eyes and this check was also fine. Mr Brown wants to thank the doctors and staff of the NHS, particularly Moorfields Hospital. Were there to be any change, he would of course make a further statement."

Number 10 indicated that the details had been released in the interests of "transparency", and stressed that there was no question of "regular" updates on the premier's condition. However, the approach could make it more difficult to hold back information about Mr Brown's health and well-being in future.

The PM has been repeatedly quizzed in interviews over his eyesight, including on the BBC's Andrew Marr show last month. During the BBC interview Mr Brown was also forced to deny rumours that he was dependent on prescription painkillers.

Some unconfirmed media reports had suggested Mr Brown might use concerns about his health as a reason for stepping down as Prime Minister ahead of the election.

Som Prasad, a consultant ophthalmologist at Arrowe Park Hospital in Merseyside, said that, although Mr Brown may not undergo more surgery on his retina, other less drastic procedures could be on the cards.

Tears can be heat-sealed by directing a laser beam of light through the pupil of the eye to produce a scar which seals the tear. An alternative would be cryotherapy treatment, where a freezing treatment is applied by a pen-shaped probe to the outside of the eye. But if the retina becomes detached - as has happened to Mr Brown twice before - "more complicated operations" may also be needed to prevent the loss of sight.